It is technically trespass. Visitors were required to sign in. However, they should be smart enough to agree that he was making a valid point, and act to improve their security, not hassle this father. If not, take it to trial and let a jury decide if he should be convicted. I’d acquit.
>>It is technically trespass. Visitors were required to sign in.<<
Disagree.
Once the person was buzzed in it is quite clearly an invitation to enter. There is no way for a person to know additional requirements unless told.
I think this was a great idea.
Something similar happened many years ago to a mainframe computer operations manager (Might be just lore). A DP auditor (we used to have such things) known to the computer operator was given access to the machine room. The auditor chatted up the operator and “accidentally” left his briefcase in the machine room.
When it was discovered a bit later, it had a note inside it with the word “boom!” written on it.
Ops manager, operator AND auditor were all immediately fired.